1. Field of the Invention
This invention pertains generally to an implantable distraction device, and more particularly to a cervical distraction device.
2. Description of the Relevant Art
Chronic back problems cause pain and disability for a large segment of the population. Adverse spinal conditions are characteristic of age. With aging, generally comes an increase in spinal stenosis (including, but not limited to, central canal and lateral stenosis), and facet arthropathy. Spinal stenosis results in a reduction of foraminal area (i.e., the available space for the passage of nerves and blood vessels) which compresses the cervical nerve roots and causes radicular pain. Extension and ipsilateral rotation of the neck further reduces the foraminal area and contributes to pain, nerve root compression, and neural injury. However, neck flexion generally increases the foraminal area.
Cervical disc herniations predominantly present with upper extremity radicular symptoms. The vast majority of these herniations do not have an associated neurologic deficit and present with pain only. A well-described treatment for cervical disc herniations is closed traction. There are a number of marketed devices that alleviate pain by pulling on the head to increase foraminal height.
Cervical disc herniations have been treated with anterior and posterior surgery. The vast majority of these surgeries are performed through an anterior approach, which requires a spinal fusion. These surgeries are expensive and beget additional surgeries due to change in biomechanics of the neck. There is a 3% incidence of re-operation after cervical spine surgery.
Therefore, an object of the present invention is to provide a minimally invasive device and surgery to increase foraminal height reduce radicular symptoms for patients with disc herniations.
At least some of these objectives will be met in the following disclosure.